Treatment of hydrocarbon oils



Patented Feb. 6, 1940 TREATMENT on HYDROOARBON oils 1 l Roland B. Day,

Amarillo,

Tex., assignor to.

Universal Oil Products Company, Chicago, Ill., a corporation of Delaware No Drawing. Application April 14, 1937,

, Serial No. 136,789

6 Claims.

. The problem of producing a stable and market- 10f able gasoline from primary cracked distillates is one of long standing and the first attempts to solveit were made with sulfuric acid which had been a successful treating reagent on miscellaneous straight run distillates prior to the extensive use oi the cracking process. The action of suliuric acid on cracked distillates, however, is not entirely satisfactory when itis desired to remove considerable quantities of sulfur compounds present] in some distillates since theacid not only acts upon these compounds and the more unsaturated oleiinic hydrocarbons such as ,diolefins but also acts upon mono olefins which are thus lost as valuable antiknockconstituents of the gasoline. Moreover, a sulfuric acid treatment requires a subsequent redistillation on ace count of the formation. of various sulfuric acid reaction products. such as organic esters, suliones, high boiling polymers, etc., and the distillation stepis an added expense. Various substitute treatments with other reagents than sulfuric acid ""530 have been tried and some have attained commercial importance such as, for example, the vapor phase treatment of cracked distillates with fullers earth, clays, and'other adsorbent materials either metal salts or oxides.

The presentinvention is concerned with a process whereby cracked distillatesmay be treated either in liquid, mixed or vapor phase with a solid granular reagent which produces results showing it to be a distinct improvement over previous types of processes employing either liquid or solid granular treating reagents. I

' In one specificembodiment the present invention comprises treatment of hydrocarbon oildistillates, particularly cracked hydrocarbon oil dis- ,tillates, with solid granular contact .materials comprising reaction products of zinc'silicates and hydrochloric acid.

It has been found that the hydrochloric acid treatment of zinc silicates such as the mineral calamine having the general formulaZnzSiO r may be made under properly controlled conditions to produce a porous. contactmaterial which 5 markedly effective in selectively removing. the.

oil vtreatments.fare accomplished both by the screen.

as such or impregnated with metals or heavy at a temperature of 220-230 F. for 18 hours and chemical action of zinc chloride and the adsorptive action of the silicic acid. By observing the proper method of preparation of thistype of treating reagent which will be described in following paragraphs, materials of high treating effi- '5 ciency and strong structure are produced, which are substantially dry and free from hydrochloric acid so that they can be safely used in metal equipment with practically no danger of corrosion if protected as far as practically possibleqo from moisture contacts.

The following instance of preparation of a treating composite in accordance with the present invention is given to illustrate the general method althoughit is to be understood thatwith 5 other types of zinc silicates either natural or synthetic," the procedure both as to relative quantities of reagents'and temperatures of treatment may be varied considerably Without departing from the scope of the invention. F2

The mineral caiamine was ground, until substantially all the particles passed a 60 mesh 1 700 parts by weight of the powdered material was then mixed with 835 parts by weight of commercial muriatic'acid of approximately ful- 38% strength until the reaction was complete. 7 The mixing was done at ordinary temperature. and considerable heat was evolved although not in amount to render the reaction uncontrollable, particularly if the mixing was done graduallym After the reaction mixture had cooled to room temperature it set to a more or less jelly-like consistency and this material was dried at a temperature of approximately 175 F. until it had hardened considerably after which it was again ,1

crushed and mixed with an equal part by weight of dry zinc oxide. An 'amountor" Water equal to one-half the weight of the mix-was then added while stirring vigorously by mechanical means until the material began to show evidences of setting. Itwas found to be important at this: point to stop the stirring just short of the point of setting to preserve the structural strength of the material.

The coarsely broken material was then heated was then ground and sized to produce particles of ironrapproximately 16-30 mesh in diameter which constituted the desired treating reagent. The fines could be added to a second batch of calarnine for treatment so that ultimately no material was lost. The particles were hygroscopic and were protected from air contacts as much, as possible prior to use. It is probable that the main compound of zinc in the composite reagent;, was the oxychloride having the formula ZnOI-ICI. The above procedure may be modified in some particulars. For example, the dried initially formed gelatinous material may be mixed with an aqueous. slurry of 1 part zinc oxide suspended bers'containing stationary masses of the granular 3. A process for refining cracked gasoline particles in a manner-generally similar to that distillate which comprises treating the distillate employed when using clays or iullers earth. in the absence of hydrochloric acid with. adry Such points as temperature, pressure, phase, and -pre-formed solid reaction product of'a zinc time of contact will depend upon the charactersilicate and hydrochloric acid, said product being (5% istics of the distillate treated and the extent of substantially devoidoi free hydrochloric acid, treating desired. In general it has been found 4. A process for refining cracked gasoline that treating reagents of the present character distillate which comprises treating the distillate. have a considerably greater selective action than in the absence of hydrochloric acid with apresimilar reagents heretofore employed and that formedzinc silicate and hydrochloricacidrethey are more effective in reducing sulfur for action product to which zinc oxide has been the same degree of removal of gum and coloradded, said product being a dry solid substanforming hydrocarbons. tially devoid of free hydrochloric acid.

The following example is introduced to show 5. A process for improving cracked hydrothe results obtainable in commercial practice by carbon vapors which comprises contacting the the process of the present invention. The gasoline vapors in the absence of hydrochloric acid with whose properties are shown in the first column a dry, pre-formed solid reaction product of a I of the table was preheated and vaporized under zinc silicate and hydrochloric acid, said product pressure and the vapors passed through stabeing substantially devoid of ,free hydrochloric tionary beds of (l) fullers earth and (2) a treatacid. f ing material prepared in accordance with the 6. A process for improving cracked hydroscheme Out ne abOVe- For poses of 'comcarbon vapors which comprises-contacting the parison the results for different throughputs are vapors in the absence of hydrochloric acid with given for each yp f reating reagent. Th a pre-iormed zinc silicate and hydrochloric acid charging stock was a cracked distillate produced reaction product to which zinc oxide has been by the intens py olysis of a mixture of Midadded, said product being a drysolid substan- 5f Continent residua. tially devoid of free hydrochloric acid.

Charging Treated withful- Treated with proc- I I stock lers earth ess reagent Pressure pounds-- 250 250 250 250 Temperature..- F.. 400 400 400 400 Bbls./ton yield 300-512 512-738 300-516 516-745 Color, Saybolt... Yellow 23 21 25 23 Color stability 18 16 22 21- Copper dish gum, gr./ cc. 416 76 48 89 w Copper dish gum, +,0.025% B5 commercial inhibitor 343 7 7. 1 3 Induction periodnuminutesu 210 200 195 Induction period +0.025 commercial inhibitor 225 415 385 l 615 580 Doctor test Positive Negative Negative Negative Negative Mercaptan sulfur, petcent 0.0 0.021 0.023 0 0 Total loss 2.5 2.5 3.0 3.0 y Polymerization loss 1.0 1.0 l 3.0 2.5

described general process may be employed in a.

number of ways to effect the treatment of hydrocarbon distillates to remove potential gum-forming compounds, to some extent reduce the sulfur content, and improve the color and odor. Treatments may be made, for example, by merely stirring the prepared composites with a liquid distillate either at ordinary or slightly elevated temperatures under reflux conditions. In other instances the liquid materials may be pumped through stationary beds of the material contained in cylindrical filter chambers in much the same manner that liquid phase adsorbent earth treatments are conducted. Where more severe treating is necessary considerably elevated temperatures of the order of 400-600 and super.- atmospheric pressures as high as 400 lbs. per square inch may be employed while the material is being pumped or vaporized through the beds of prepared reagents. A particular application of the process consists in passing the vapors directly from a cracking plant through chamthe treatment according to the present process yielded results considerably better than the fullers earth treatment. This is evident in the higher color after treatment for a' given yield, the higher color stability, the lower copper dish gum and the higher susceptibility to reduction in gum content-and increase in induction period after the addition of a small percentage of a commercial inhibitor. Furthermore the mer'captan sulfur in the product from the process treat-" ment was substantially zero.

The nature of theinvention and its practical aspects can be seen from the foregoing specification and limited numerical data though the scope of the invention is not intended to be limited unduly by either section. v

I claim as my invention:"

1. A process for refining hydrocarbon oils which comprises contacting the oil in the absence,

of hydrochloric'acid with a ,dry, pre-formed solid reaction product of a zinc silicate and hydrochloric acid, said product being substantially devoid of free hydrochloric acid.

2. A process for refining hydrocarbon oils which comprises contacting the oil in theabsence 1 of hydrochloric acid with a pre-formed zinc silicate and hydrochloric acid reaction product to which zinc oxide has been added, said product, being a dry solid substantially devoid of free hydrochloric acid.

I ROLAND B. DAY. i 

